Symfony2: class 'Doctrine\Common\Collections\ArrayCollection' was not found in the chain configured namespaces

Question

Error occurs when attempting to persist a one-to-many relationship. In particular, a client may have multiple household members; a given household member is associated with one and only one client. [I am new to Symfony so errors are expected!] Your guidance gratefully accepted. N.B. Alternate controller snippet below yields integrity constraint error by trying to set the client's id in the household table to null. Clients Entity snippet ``` namespace Mana\AdminBundle\Entity; use Doctrine\ORM\Mapping as ORM; use Doctrine\Common\Collections\ArrayCollection; /** * Mana\AdminBundle\Entity\Clients * * @ORM\Table(name="clients") * @ORM\Entity */ class Clients { protected $members; public function __construct() { $this->members = new ArrayCollection(); } public function getMembers() { return $this->members; } public function setMembers(ArrayCollection $members) { $this->members = $members; } /** * @var integer $id * * @ORM\Column(name="id", type="integer", nullable=false) * @ORM\Id * @ORM\Ge…

Accepted Answer

The times I have gotten this to work, I did not

```
use Doctrine\Common\Collections\ArrayCollection; 
```

I just

```
$this->field = new \Doctrine\Common\Collections\ArrayCollection();
```

in my constructor.

Also, you may want to consider adding Household (which appear to be the members in clients) as an entity form:

```
->add('members', 'entity', array(
    'type' => new HouseholdType(),
    'allow_add' => true, 
    'by_reference' => false,
    ));
```

Symfony2: class 'Doctrine\Common\Collections\ArrayCollection' was not found in the chain configured namespaces

Solution

Problem